6 BR 600yd build

[rangertim]

What lead or freebore due I need for 6 BR with 90 to 107gr Is there a middle of the road.I'm using a a gain twist 8.75 to 8.35 Krieger. Thanks

 

[dreever]

I know a lot of guys will disagree with me on this, but I personally prefer using a reamer with .060 freebore. Now, a lot of guys will scream "That's to short!" well it isn't. I use Berger 105 VLD's with the boattail/ bearing surface junction right at the bottom of the case neck on a fresh barrel. As the throat wears, and round count increases I chase the lands to maintain my .013 into the lands seating depth. Sure, you can go with loooong freebores to increase powder capacity, but is this really needed?
My standard go to load of Berger 105 VLD, Lapua neck turned brass, CCI 450 primer on top of 30.5 grains of Varget in every barrel I've chambered with this reamer has shot an inch or better at 500 meters.
My barrels are Kreiger 8 twist heavy Varmint contours, .237 bore, 26 inches long.
If you feel you just have to go with a longer freebore I would suggest no longer than .104.
This is just my opinion.

Danny

 

[cmillard]

i have .115FB on my 6BR. it shoots lights out with 107 sierras and 30.0 varget.

 

[tclaunch]

The long neck on the standard BR case is much more forgiving on throat length. My 6BR reamer was one of the first I ordered and Kiff suggested a .104". I went with that and it seems to cover all the bases with various bullets not crowding any one in particular. I have some new Bib 108BT in that I have not tried in the 6BR case, as those require a long throat. They may not sit in the neck to my liking. I did order those with a particular reamer in mind, not in 6BR.

 

[forsyth793]

Dreever...

What Numbers are you getting with that load? It seems that if I get above 2790 FPS accuracy diminishes. I am using 30 Varget with Moly and 108 Bergers.....

Spike

 

[dreever]

Spike,

2790 seems low for 30 grains of Varget. Then again your shooting moly with ??? freebore, so you might want to up that charge and/or switch to a tighter bushing to get your pressures and velocities up. I check pressure by measuring case head expansion from new brass and as long as I'm below .001 on the first firing I'm happy.
In three 6BR barrels that I have chambered with my reamer using the load I mentioned I'm getting from 2920 in my newest barrel, 2940 in the second, and 2960 in the third (3rd being a 28 incher). The short freebore does increase pressure so that may account for my higher numbers or simply the difference in chronographs.
I'm more concerned with low E.S. numbers than velocity (mine are all under 10fps) and how it groups out to 600 yards. The slowest barrel of the three is shooting better than the other two, but then again different actions and stocks may just figure into that also.

Danny

 

[Rtheurer]

Tim
My reamer is a .104 FB. Its a good fit for the 107 SMK and the 105 Amax. The only problem is that I shoot 105 Berger VLD's Exclussively in that rifle and I should have gone the .090 route knowing what I know now. Shoots good as it sits right now with no issues though.

What ever you decide on I would encourage you to get a Harrell Sizing Die. He matches it to YOUR chamber, they are a jewell to work with. wonderful product.

RussT